In　this　work,　we　study　the　thermoelectric　properties　of　the　parallel-coupled　double　quantum　dot　connected　to　Luttinger　liquid　(LL)　leads.　By　applying　nonequilibrium　Green＇s　function　methods,　the　expressions　of　the　electron　current,　heat　currents,　and　transport　coefficients　are　derived.　We　mainly　focus　on　the　effect　of　intralead　Coulomb　interaction　and　the　spatial　asymmetry　of　the　system.　Various　causes　for　the　enhancement　of　the　thermoelectric　efficiency　are　investigated.　We　find　that　Coulomb　interactions　in　the　LL　not　only　enhance　quantum　interference　but　also　considerably　enhance　thermoelectric　effects.　For　moderately　strong　intralead　interaction,　the　figure　of　merit　can　be　considerably　high　and　reach　over　60　in　the　case　of　weakly　coupled　to　LL　leads　and　detuning　of　the　energy　levels,　while　in　the　case　of　strongly　coupled　to　LL　leads　and　the　two　aligned　levels,　the　figure　of　merit　approaches　8.　The　quantum　interference　induced　by　the　Coulomb　interaction　yields　a　very　high　thermoelectric　efficiency　when　the　intralead　interaction　is　very　strong.　These　results　may　provide　a　design　rule　for　the　development　of　high-efficiency　thermoelectric　devices　and　facilitate　optimization　of　device　performance.　©　2023　Elsevier　B.V.